| 2635 | | [=#canopy '''Canopy:]\\\\ |
| 2636 | | '''Attention:''' Starting at '''revision 1485''', the plant canopy model is fully modularized. Therefore, the plant canopy model is now steered using the new NAMELIST [../canpar# canopy_par], and no longer in NAMELIST {{{inipar}}}. |
| 2637 | | ||='''Parameter Name''' =||='''[../fortrantypes FORTRAN]\\[../fortrantypes Type]''' =||='''Default\\Value''' =||='''Explanation''' =|| |
| 2638 | | |---------------- |
| 2639 | | {{{#!td style="vertical-align:top;width: 150px" |
| 2640 | | [=#canopy_mode '''canopy_mode'''] |
| 2641 | | }}} |
| 2642 | | {{{#!td style="vertical-align:top;width: 50px" |
| 2643 | | C*20 |
| 2644 | | }}} |
| 2645 | | {{{#!td style="vertical-align:top;width: 75px" |
| 2646 | | 'block' |
| 2647 | | }}} |
| 2648 | | {{{#!td |
| 2649 | | Canopy mode.\\\\ |
| 2650 | | Besides using the default value, that will create a horizontally homogeneous plant canopy that extends over the total horizontal extension of the model domain, the user may add code to the user interface (see [#3.5.1 3.5.1]) subroutine {{{user_init_plant_canopy}}} to allow further canopy modes.\\\\ |
| 2651 | | The setting of '''canopy_mode''' becomes only active, if [#plant_canopy plant_canopy] has been set ''.T.'' and a non-zero [#drag_coefficient drag_coefficient] has been defined.\\\\ |
| 2652 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#canopy_mode canopy_par]. |
| 2653 | | }}} |
| 2654 | | |---------------- |
| 2655 | | {{{#!td style="vertical-align:top" |
| 2656 | | [=#cthf '''cthf'''] |
| 2657 | | }}} |
| 2658 | | {{{#!td style="vertical-align:top" |
| 2659 | | R |
| 2660 | | }}} |
| 2661 | | {{{#!td style="vertical-align:top" |
| 2662 | | 0.0 |
| 2663 | | }}} |
| 2664 | | {{{#!td |
| 2665 | | Average heat flux that is prescribed at the top of the plant canopy.\\\\ |
| 2666 | | If [#plant_canopy plant_canopy] is set ''.T.'', the user can prescribe a heat flux at the top of the plant canopy. |
| 2667 | | It is assumed that solar radiation penetrates the canopy and warms the foliage which, in turn, warms the air in contact with it.\\\\ |
| 2668 | | '''Note:'''\\ |
| 2669 | | Instead of using the value prescribed by [#surface_heatflux surface_heatflux], the near surface heat flux is determined from an exponential function that is dependent on the cumulative leaf_area_index (Shaw and Schumann (1992, Boundary Layer Meteorol., 61, 47-64)).\\\\ |
| 2670 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#cthf canopy_par]. |
| 2671 | | }}} |
| 2672 | | |---------------- |
| 2673 | | {{{#!td style="vertical-align:top" |
| 2674 | | [=#drag_coefficient '''drag_coefficient'''] |
| 2675 | | }}} |
| 2676 | | {{{#!td style="vertical-align:top" |
| 2677 | | R |
| 2678 | | }}} |
| 2679 | | {{{#!td style="vertical-align:top" |
| 2680 | | 0.0 |
| 2681 | | }}} |
| 2682 | | {{{#!td |
| 2683 | | Drag coefficient used in the {{{plant_canopy_model}}}.\\\\ |
| 2684 | | This parameter has to be non-zero, if the parameter [#plant_canopy plant_canopy] is set ''.T.''.\\\\ |
| 2685 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#canopy_drag_coeff canopy_par], and parameter '''drag_coefficient''' is renamed [../canpar#canopy_drag_coeff canopy_drag_coeff]. |
| 2686 | | }}} |
| 2687 | | |---------------- |
| 2688 | | {{{#!td style="vertical-align:top" |
| 2689 | | [=#lad_surface '''lad_surface'''] |
| 2690 | | }}} |
| 2691 | | {{{#!td style="vertical-align:top" |
| 2692 | | R |
| 2693 | | }}} |
| 2694 | | {{{#!td style="vertical-align:top" |
| 2695 | | 0.0 |
| 2696 | | }}} |
| 2697 | | {{{#!td |
| 2698 | | Surface value of the leaf area density (in m^2^/m^3^).\\\\ |
| 2699 | | This parameter assigns the value of the leaf area density '''lad''' at the surface (k=0). Starting from this value, the leaf area density profile is constructed with [#lad_vertical_gradient lad_vertical_gradient] and [#lad_vertical_gradient_level lad_vertical_gradient_level].\\\\ |
| 2700 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#lad_surface canopy_par]. |
| 2701 | | }}} |
| 2702 | | |---------------- |
| 2703 | | {{{#!td style="vertical-align:top" |
| 2704 | | [=#lad_vertical_gradient '''lad_vertical_gradient'''] |
| 2705 | | }}} |
| 2706 | | {{{#!td style="vertical-align:top" |
| 2707 | | R(10) |
| 2708 | | }}} |
| 2709 | | {{{#!td style="vertical-align:top" |
| 2710 | | 10 * 0.0 |
| 2711 | | }}} |
| 2712 | | {{{#!td |
| 2713 | | Gradient(s) of the leaf area density (in m^2^/m^4^).\\\\ |
| 2714 | | This leaf area density gradient holds starting from the height level defined by [#lad_vertical_gradient_level lad_vertical_gradient_level] (precisely: for all uv levels k where zu(k) > lad_vertical_gradient_level, lad(k) is set: lad(k) = lad(k-1) + dzu(k) * '''lad_vertical_gradient''') up to the level defined by [#pch_index pch_index]. Above that level lad(k) will automatically be set to 0.0. A total of 10 different gradients for 11 height intervals (10 intervals if lad_vertical_gradient_level(1) = 0.0) can be assigned. The leaf area density at the surface is assigned via [#lad_surface lad_surface].\\\\ |
| 2715 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#lad_vertical_gradient canopy_par]. |
| 2716 | | }}} |
| 2717 | | |---------------- |
| 2718 | | {{{#!td style="vertical-align:top" |
| 2719 | | [=#lad_vertical_gradient_level '''lad_vertical_gradient_level'''] |
| 2720 | | }}} |
| 2721 | | {{{#!td style="vertical-align:top" |
| 2722 | | R(10) |
| 2723 | | }}} |
| 2724 | | {{{#!td style="vertical-align:top" |
| 2725 | | 10 * 0.0 |
| 2726 | | }}} |
| 2727 | | {{{#!td |
| 2728 | | Height level from which on the gradient of the leaf area density defined by [#lad_vertical_gradient lad_vertical_gradient] is effective (in m).\\\\ |
| 2729 | | The height levels have to be assigned in ascending order. The default values result in a leaf area density that is constant with height up to the top of the plant canopy layer defined by [#pch_index pch_index]. For the piecewise construction of temperature profiles see [#lad_vertical_gradient lad_vertical_gradient].\\\\ |
| 2730 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#lad_vertical_gradient_level canopy_par]. |
| 2731 | | }}} |
| 2732 | | |---------------- |
| 2733 | | {{{#!td style="vertical-align:top" |
| 2734 | | [=#leaf_surface_concentration '''leaf_surface_concentration'''] |
| 2735 | | }}} |
| 2736 | | {{{#!td style="vertical-align:top" |
| 2737 | | R |
| 2738 | | }}} |
| 2739 | | {{{#!td style="vertical-align:top" |
| 2740 | | 0.0 |
| 2741 | | }}} |
| 2742 | | {{{#!td |
| 2743 | | Concentration of a passive scalar at the surface of a leaf (in K m/s).\\\\ |
| 2744 | | This parameter is only of importance in cases in that both, [#plant_canopy plant_canopy] and [#passive_scalar passive_scalar], are set ''.T..'' The value of the concentration of a passive scalar at the surface of a leaf is required for the parametrisation of the sources and sinks of scalar concentration due to the canopy.\\\\ |
| 2745 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar# canopy_par], and parameter '''leaf_surface_concentration''' is renamed [../canpar#leaf_surface_conc leaf_surface_conc]. |
| 2746 | | }}} |
| 2747 | | |---------------- |
| 2748 | | {{{#!td style="vertical-align:top" |
| 2749 | | [=#pch_index '''pch_index'''] |
| 2750 | | }}} |
| 2751 | | {{{#!td style="vertical-align:top" |
| 2752 | | I |
| 2753 | | }}} |
| 2754 | | {{{#!td style="vertical-align:top" |
| 2755 | | 0 |
| 2756 | | }}} |
| 2757 | | {{{#!td |
| 2758 | | Grid point index (scalar) of the upper boundary of the plant canopy layer.\\\\ |
| 2759 | | Above '''pch_index''' the arrays of leaf area density and [#drag_coeffient drag_coeffient] are automatically set to zero in case of [#plant_canopy plant_canopy] = ''.T.''. Up to '''pch_index''' a leaf area density profile can be prescribed by using the parameters [#lad_surface lad_surface], [#lad_vertical_gradient lad_vertical_gradient] and [#lad_vertical_gradient_level lad_vertical_gradient_level].\\\\ |
| 2760 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar#pch_index canopy_par]. |
| 2761 | | }}} |
| 2762 | | |---------------- |
| 2763 | | {{{#!td style="vertical-align:top" |
| 2764 | | [=#plant_canopy '''plant_canopy'''] |
| 2765 | | }}} |
| 2766 | | {{{#!td style="vertical-align:top" |
| 2767 | | L |
| 2768 | | }}} |
| 2769 | | {{{#!td style="vertical-align:top" |
| 2770 | | .F. |
| 2771 | | }}} |
| 2772 | | {{{#!td |
| 2773 | | Switch for the plant canopy model.\\\\ |
| 2774 | | If '''plant_canopy''' is set ''.T.'', the plant canopy model of Watanabe (2004, BLM 112, 307-341) is used.\\ |
| 2775 | | The impact of a plant canopy on a turbulent flow is considered by an additional drag term in the momentum equations and an additional sink term in the prognostic equation for the subgrid-scale TKE. These additional terms depend on the leaf drag coefficient (see [#drag_coefficient drag_coefficient]), and the leaf area density (see [#lad_surface lad_surface], [#lad_vertical_gradient lad_vertical_gradient], [#lad_vertical_gradient_level lad_vertical_gradient_level]). The top boundary of the plant canopy is determined by the parameter [#pch_index pch_index]. For all heights equal or larger than zw(k=pch_index), the leaf area density is 0 (i.e. there is no canopy at these heights!).\\ |
| 2776 | | By default, a horizontally homogeneous plant canopy is prescribed, if '''plant_canopy''' is set ''.T.''. However, the user can define other types of plant canopies (see [#canopy_mode canopy_mode]).\\\\ |
| 2777 | | If '''plant_canopy''' and [#passive_scalar passive_scalar] are set ''.T.'', the canopy acts as an additional scalar source or sink, respectively. The source/sink strength depends on the scalar concentration at the leaf surface, which generally does not vary with time in PALM, and which can be specified with parameter [#leaf_surface_concentration leaf_surface_concentration].\\\\ |
| 2778 | | Additional heating by the plant canopy is taken into account, if the default value of parameter [#cthf cthf] is altered in the parameter file. In that case, the value of [#surface_heatflux surface_heatflux] specified in the parameter file is not used in the model. Instead, the near-surface heat flux is derived from an exponential function that depends on the cumulative leaf area index.\\\\ |
| 2779 | | '''plant_canopy''' = ''.T.'' is only allowed with a non-zero [#drag_coefficient drag_coefficient].\\\\ |
| 2780 | | '''Attention:''' Starting at '''revision 1485''', steering parameter '''plant_canopy''' no longer exists. This FORTRAN {{{LOGICAL}}} is now automatically set to ''.TRUE.'' if the NAMELIST [../canpar# canopy_par] is included in the parameter file ({{{_p3d}}}). |
| 2781 | | }}} |
| 2782 | | |---------------- |
| 2783 | | {{{#!td style="vertical-align:top" |
| 2784 | | [=#scalar_exchange_coefficient '''scalar_exchange_coefficient'''] |
| 2785 | | }}} |
| 2786 | | {{{#!td style="vertical-align:top" |
| 2787 | | R |
| 2788 | | }}} |
| 2789 | | {{{#!td style="vertical-align:top" |
| 2790 | | 0.0 |
| 2791 | | }}} |
| 2792 | | {{{#!td |
| 2793 | | Scalar exchange coefficient for a leaf (dimensionless).\\\\ |
| 2794 | | This parameter is only of importance in cases in that both, [#plant_canopy plant_canopy] and [#passive_scalar passive_scalar], are set ''.T.''. The value of the scalar exchange coefficient is required for the parametrisation of the sources and sinks of scalar concentration due to the canopy.\\\\ |
| 2795 | | '''Attention:''' Starting at '''revision 1485''', steering parameters for the plant canopy model belong to the new NAMELIST [../canpar# canopy_par], and parameter '''scalar_exchange_coefficient''' is renamed [../canpar#leaf_scalar_exch_coeff leaf_scalar_exch_coeff]. |
| 2796 | | }}} |
| 2797 | | |---------------- |
| 2798 | | [[BR]] |
| 2799 | | |